4 ms·

A tiny additional detail - sensor alternates not because of some arbitrary adhoc rule but because aircraft always uses sensor on main pilot’s side and main pilo

A tiny additional detail - sensor alternates not because of some arbitrary adhoc rule but because aircraft always uses sensor on main pilot’s side and main pilot’s seat alternates each flight. Still boggles my mind how utterly incompetent and borderline malicious everybody involved in designing and implementing this system are. I wish we’d see some people jailed and Boeing hit with billions of dollars fines but chances are slim.

dTal 7y ago
I am aware of that detail. But why? Why does the aircraft always use the sensor on the main pilot's side? That itself seems like an arbitrary, ad-hoc rule. What does global AOA state data have to do with where the pilot's ass is currently located? Why even have two sensors at all, if you only use one at a time? Given you have two sensors, why not fuse them? Any fusion logic is more intelligent than what they did. I'm sure each decision seemed logical to the person making it. But from a bird's eye view, it gives the impression of poor coordination - Team A [hardware] thinks "clearly we need multiple AOA sensors for redundancy". Team B [software] thinks "AOA isn't all that important, we barely use it and failure is non-critical. Sensor fusion is hard, let's go shopping!".
- keymone 7y ago
  Yeah, I agree, it’s still arbitrary, just on different level.
  - dTal 7y ago
    I think it's the same level. There's no evident reason why "pilot's side" is any less arbitrary than "flip a coin". Was there actually an a-priori specification that AOA sensors must always be on the pilot's side? If there is such a specification, I can't find it - Google searches for stuff like 'AOA sensors pilots side' return mostly articles about the MAX. Nor can I see a good reason for it that is concordant with the existence of paid extra feature of a disagreement light - no particular significance or weight is given to the pilot's side sensor. It sure feels like this is a post-hoc rationalization for only writing software to handle one AOA vane at a time despite being equipped with two.
    - keymone 7y ago
      My speculation is that there is a class of instruments that get prioritized depending on main pilot’s side. It’s easy to assume there is a valid reason for that (ability to override and whatnot). Why would a sensor of which there are two, fall into that category - is a puzzle.

dTal 7y ago

I am aware of that detail. But why? Why does the aircraft always use the sensor on the main pilot's side? That itself seems like an arbitrary, ad-hoc rule. What does global AOA state data have to do with where the pilot's ass is currently located? Why even have two sensors at all, if you only use one at a time? Given you have two sensors, why not fuse them? Any fusion logic is more intelligent than what they did. I'm sure each decision seemed logical to the person making it. But from a bird's eye view, it gives the impression of poor coordination - Team A [hardware] thinks "clearly we need multiple AOA sensors for redundancy". Team B [software] thinks "AOA isn't all that important, we barely use it and failure is non-critical. Sensor fusion is hard, let's go shopping!".

keymone 7y ago
Yeah, I agree, it’s still arbitrary, just on different level.
- dTal 7y ago
  I think it's the same level. There's no evident reason why "pilot's side" is any less arbitrary than "flip a coin". Was there actually an a-priori specification that AOA sensors must always be on the pilot's side? If there is such a specification, I can't find it - Google searches for stuff like 'AOA sensors pilots side' return mostly articles about the MAX. Nor can I see a good reason for it that is concordant with the existence of paid extra feature of a disagreement light - no particular significance or weight is given to the pilot's side sensor. It sure feels like this is a post-hoc rationalization for only writing software to handle one AOA vane at a time despite being equipped with two.
  - keymone 7y ago
    My speculation is that there is a class of instruments that get prioritized depending on main pilot’s side. It’s easy to assume there is a valid reason for that (ability to override and whatnot). Why would a sensor of which there are two, fall into that category - is a puzzle.